This invention relates to product labels, and more particularly, to backlit labels.
Labels are used today on products to present important information, such as a company logo, an instruction, or a warning. One type of label used in electronic products is a xe2x80x9cbacklitxe2x80x9d label, in which a light source is positioned behind the label to make the background brighter and characters in the label appear sharper.
The backlighting can be derived from many different sources. In one case, the source may be specifically dedicated to the label. For instance, a flat light, such as an electroluminiscent (EL) light, may be integrated into an electronic label to specifically light the label when power is applied. Alternatively, the backlight may be derived from a source separate from the label. Light from an LCD (liquid crystal display) screen, for example, may be redirected as a backlight onto a passive label. The Apple Powerbook notebook computer employs this technique by arranging a passive logo on the backside of the LCD and piping light leaked from the LCD backlight onto the logo to illuminate the logo.
Conventional backlit labels are plagued by an appearance problem in that one state, either xe2x80x9conxe2x80x9d or xe2x80x9coffxe2x80x9d, does not look nearly as good as the other state. Typically, backlit labels look good in the xe2x80x9conxe2x80x9d state, but not in the xe2x80x9coffxe2x80x9d state. Rather, when xe2x80x9coffxe2x80x9d, the backlit label appears as if it is simply turned off, often looking worse than a passive label.
One complicating factor is that the backlight should be bright enough to be visible in a high ambient light environment. In dual-mode products such as wristwatches, designers assume that the backlit state will be used only in dim environments. As a result, the light does not have to be very bright and the xe2x80x9coffxe2x80x9d state appearance is less important because it cannot be seen.
Accordingly, there is a need for a backlit label that is visually appealing in both the xe2x80x9conxe2x80x9d and xe2x80x9coffxe2x80x9d states, as well as in both light and dark environments.
A backlit label includes a transparent element and a transflective element positioned at the backside of the transparent element. The transparent element passes light bi-directionally, whereas the transflective element passes light received from a first direction and reflects light received from an opposite direction. A backlight source, which may or may not be integrated with the label, produces backlighting for the label. The transflective element passes the backlight that emanates from behind the label out through the transparent element. However, for ambient light received from in front of the label, the transflective element reflects the ambient light back out through the transparent element. As a result, the label is visually appealing in both the xe2x80x9conxe2x80x9d and xe2x80x9coffxe2x80x9d states and exhibits distinctly different looks in the two states. Moreover, the label performs well in both light and dark environments.